Hi Gartemua ,

Here in Oz we tend to use composted ( Pine ) bark as a medium for growing Billbergia ,the pieces are roughly from 1/2 to 1 cm size ,little fertiliser is used and it must be very low in Nitrogen ( 2 % ) or leaves lose their colour till the nitrogen is used up ,allthough this effect is less noticeble on the Helicoids ( Brasiliansis ,Rosea ,Venezualiana etc ,) is this of any help ?
Jack

My all-around brom mix is 50/50 mix of small orchid bark nuggets and high quality potting soil with some handfuls of perlite and pumice thrown in.

I have mine under a live oak in plenty of pine bark and oak leaves. That way they get some moisture retention and plenty of air for the roots!

Thank you very much, the issue has been exhausted.